“…Following this concept over the past 30 years, some researchers (Davis, 1980(Davis, , 1982Coldwell, 1983;Zhao, 1993;Zhu, 2001 ;Smierzchalski, 2001 ;Kijima, 2001Kijima, , 2003Pietrzykowski, 2004Pietrzykowski, , 2006Pietrzykowski, , 2008 have also presented various ship domains with different shapes and sizes taking into account different factors affecting the domain parameters. Ship domains play a very important role in risk assessments (Pietrzykowski, 2008 ;Szlapczynski, 2006), collision avoidances (Hwang, 2002;Kao, 2007 ;Wilson, 2003), marine traffic simulations (Lisowski, 2000) and optimal trajectory planning (Smierzchalski, 2000), etc. Statistics show that human errors have caused 80% of marine accidents for which the main reason is inappropriate assessments of the navigational situation and the consequent wrong decisions.…”